Zero carbon energy grids need nuclear in the short term, study finds

Currently, gaps in energy production from wind and solar are often replaced by power generation from natural gas. In a zero-emission electricity system, another way is needed to provide electricity when renewables are not generating energy.

“Renewable energy sources like wind and solar are great for reducing carbon emissions,” said lead researcher Lei Duan from the Carnegie Institution for Science.

“However, the wind and Sun have natural variation in their availability from day to day, as well as across geographic regions, and this creates complications for total emissions reduction.”

Previous studies have shown that curbing 80 per cent of carbon emissions can be achieved by ramping up wind and solar power harvesting installations.

However, gaps between supply and demand created by this variability in natural resources would require significant infrastructure changes, such as massive expansions in energy storage and transmission capabilities, as well as in energy generating infrastructure.

“To nail down that last 10 or 20 per cent of decarbonisation, we need to have more tools in our toolbox and not just wind and solar,” said Ken Caldeira who also worked on the study.

The team investigated the wind and solar resources of 42 countries and used this information to evaluate the ability of nuclear power to provide low-cost energy and replace natural gas as a backup energy source.

Their analysis focused on identifying which countries would benefit from exploring nuclear power as an option for their energy suite sooner rather than later.

They found that in countries such as the US, which have the right geographic and climate conditions for generating ample wind power, nuclear would not be deployed until it was needed to get over the last remaining hurdles of decarbonisation. In countries with poorer wind resources, such as Brazil, strategic use of nuclear power could enable a faster transition away from carbon.

“Under strict greenhouse gas emission controls, reliable power generation provided by nuclear power has a lot of potential value in the electricity grid for most nations,” Duan explained.

“Places with poor wind resources can benefit from nuclear earlier in the path to zero emissions, whereas places with very good wind resources would only need it to get rid of the last traces of carbon emissions.”

Caldeira added: “Our analysis looked at the cheapest way to eliminate carbon dioxide emissions, assuming today’s prices. We found that at today’s price, nuclear is the cheapest way to eliminate all electricity-system carbon emissions nearly everywhere.

“However, if energy storage technologies became very cheap, then wind and solar could potentially be the least-cost path to a zero-emission electricity system."

In our latest issue, E&T looks at the part that nuclear power can play in helping countries realise the goal of net zero, with the UK nuclear energy sector for one experiencing new growth as a result.